Spark-plug.



F. ROBINSON.

SPARK PLUG.

APPLICATION FILED JAN. 15. 1911.

1,242,375. Patented Oct. 9,1917.

OFFICE.

FRAN K ROBINSON, OF 613105.60, ILLINDIS.

sranx-rnue.

-"To all whom it may concern:

Be it known that I, FRANK ROBINSON, a citizen of the United States, and a resident of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Spark- Plugs; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, and to the numerals of reference marked thereon, which form a part of this specification.

This invention relates to an improved form of spark plug constructed to be practically self-cleaning, and having its parts so arranged that those parts liable to become fouled or damaged may be readily removed for cleaning or replacement without requiring the complete removal of the entire plug from an engine cylinder in which it is mounted.

It is an object of this invention to'provide an improved form of spark plug adapted to permit removal of certain of the parts thereof for cleaning without detachment of the entire plug from a cylinder in which it is connected.

It is also an object of this invention to construct a spark plug having a core made up of an insulating member and a metallic member adapted. to be readily removed and cleaned without detaching the entire plug from its mounting.

It is a further object of this invention to provide a spark plug wherein a combustion chamber is formed by a tubular insulating core member having an enlarged recess therein registering with the opening in a cylindrical metallic core member, and in which the 'core members are removably locked in a metallic casing- 'by a lock nut permitting cleaning of the parts liable to become fouled without detachment of the entire spark plug from a cylinder. on which it is mounted.

It is furthermore an important object of this invention to construct a spark plug in which a combustion chamber is formed by two core members removably locked one upon the other within a shell, with the lower core member seated to hold one of the ignition terminals in position to form a suitable spark gap between a second ignition termi- 'nal associated with the upper core member, said terminals being practlcally self-cleaning. and arranged for removal fr th Specification .1 Letters Patent.

Patented Oct. 9, 1917.

Application filed Januafy 15, 191?. Serial 110. 142,365.

. more fully described.

On the drawings:

Figure 1 is a side elevational view of a spark plug embodying the principles of my invention.

Fig. 2 is a top plan view thereof.

Fig. 3 is a section taken on line 33 of Fig. 2. v

Fig. 4: is a section taken on line H of Fig. 3.

Fig. 5 is a section taken on line 5-5 of Fig. 3;

Fig. 6 is a central vertical section taken through the knurled conductor cap.

Fig. 7 is a side elevational view of the spark plug having the conductor cap replaced by a lock nut and a priming mechanism, with parts shown in section.

As shown on the drawings:

The reference numeral 1, indicates a spark plug sleeve or shell, having an externally threaded plug-2, integrallyformed on the lower end thereof, and an internally threaded integral hexagonal portion 3, formed on the upper end thereof alfording a nut for receiving a wrench engaged therewith to permit the spark plug sleeve to be rigidlyv but removably engaged into -a suitable threaded aperture formed in an engine cyl idly secured thereto by means of a rivet 7,

or other suitable means projecting upwardly through the aperture in said enlarged portion, is an ax ally disposed vertical spindle llO - ing upwardly out of the-sleeve 1, and having ing a chamber into which the spark terminal or conductor 8, formed with an enlargement its upper end to hold a downwardly 1, and bearing "upon the ring plate 4, is a 1 metal cylindrical lower core member 12, eX- tending upwardly to about the height of the spindle enlargement 9'. The lower coremember 12, forms the lower half 13, of a combustion chamber in which the spindle and baille plate are located, as clearly shown in Fig. 3. Also fitting within said sleeve 1,

in theupper halfthereof, is a relatively long.

tubular open core member 14, of porcelain or other sultaole msulatmg matenal pro ectan enlarged portion-or base 15, integrally formed at the lower endthereof which fits snugly againsttheinn'er walls of said shell 1,;and seats upon the upper end of the lower n etal core member 12. The ev arged core portion 15, has formed therein the upper halflfi, of the combustion chamber, aiiordor'terminal tip 11, projects to within a short distance of the lower outwardly flanged spark terminal end '17, of a conductor tube 18, mounted within the tubular upper core -mem.ber 14, and having its upper end exteriorly threaded, asjdenoted by the reference numeral 19, which projects upwardly beyond the upper end of said core member 14.

Removably threaded upon the upper threaded end 19, of the conductor tube 18, is a lock nut 19, and knurled terminal. connector cap 20, for clamping a conductor wire (not shown) in position around the upper end of said conductor tube.- To form an air-tight it at the upper end. of the tube 18, the connector cap 20, has integrally formed on the interior thereof, a downwardly directed stem or finger 21, which lite into the upper end of the opening in said tube when said cap 20, is threadedthereon. For remova-bly holding the ring plate a, the

lower metallic core member 12, and theupper insulating core member 14, in position within said sleeve 1, a threaded gland or look nut 22, is threaded into the upper hexagonal end 3, of the sleeve, ,and presses against suitable packing, resting on the upper end of the enlarged core portion 15, to clamp said parts in place sealed and properly alined within the sleeve.

In the formrof spark plug shown in Fi 7, the construction is similar to that of the spark plug shown in Figs. 1 to 6, with the exception that the connector cap 20, lsreplaced by a knurled lock nut 23, and a priming mechanism 21, both threaded upon the upper projecting threaded end of theconductor tube 18. An ignition wire or con doctor maybe readily attached to the spark plug around the tube 18, and between the lock nut 23, and the priming mechanism 24.

It will be noted from the construction of the spark plug as described, that the various parts within the sleeve of the spark plug may be readily removed or replaced for cleaning or repairs without requiring the complete removal of the spark plug from an engine cylinder to which it is attached. I am also aware that various details of construction may be varied through a wide range without departing from the principles of this invention, and I therefore do not purpose limiting the patent granted otherwisethan necessitated by the prior art.

I'claim as my invention:

1. In a spark plug of the class described, sleeve member adapted to be threaded into the wall of an engine cylinder, chambered insuhtting and metallic core members removably mounted therein to register with one another to form a eombustionchamber, and spark terminals projecting into said combustion chamber to within a short distance'oi one another to form a spark gap.

In a spark plug of the class described, a sleeve adapted to be threaded into the wall of an engine cylinder, a lower chambered metallic core member seated therein, an upper chambered insulating core member within said slee've and mounted upon said lower core member with the chambers registering with one another to form a combustion chamber, a spark terminal associated with each of said core members projecting into the combustion chamber to form a spark gap between adjacent ends thereof, and means for removably locking said core members within said sleeve.

In a spark plug of the class described, a sleeve, a chambered metallic core member seated therein, a chambered insulating core member within said sleeve resting upon said metallic core member, said core members arranged with their chambersregistering with lot one another to afford a combustion chamber,

. hav ng a chamber therein to register with the chamber in. the lower core member to afl'ord a combustion chamber, a. conductor tube in said passaged upper core member vprojecting into said combustion chamber to said upper co're member for removably holding the spark. plug parts within said sleeve. 5. In a device of the class described, a

sleeve, a metal plate stamping seated therein, a metallic lower core member mounted thereon having a "chamber therein a spark terminal rigidly secured upon said metal plate stamping projecting upwardly into said chamber, baflle. cleaning means mounted.

thereoman insulating upper core member in said sleeverestlng upon said lower core member and having a chamber therein. registering with the chamber in said lower core member to afford a combustion chamber, a second spark terminal associated with the insulating upper core member projecting into said combustion chamber to a point above the first mentioned spark terminal to afforda'spark gap, and means 'for remov- 1 ably locking said core members within said sleeve. l p 6. A spark plug comprisinga shell, a charm bered lower metallic core member therein, a

chambered upper insulating core 'member within said shell registerin with said lower core member to form a com ustion chamber, and a spark terminal associated with each of said core members projecting into said combustion chamber to within a short distance of one another to form a spark gap.

7 A spark plug comprising a shell, and a core havinga combustion chamber therein removably mounted Within said shell and comprising a lowenmetallic core member and an upper insulating core member, registering with one another toform said combustion chamber.

8. In a device of the class described, a. sleeve, a lowerand an upper core member seated therein, a combustion chamber formed by said core members, spark terminals progecting into said combustion chamber, and

means for removably lockin'g said core members Within said sleeve,

In testimony. whereof I have hereunto subscribed my name in the presence of two subscribing witnesses.

' FRANK ROBINSON. Witnesses:

FRED EQPAESLER, LEON M. BEIBSTEIN. 

